International Journal of Occupational Hygiene 2012. 4(1):6-9.

Risk Assessment of Exposure to Gases Released by Welding Processes in Iranian Natural Gas Transmission Pipelines Industry


Exposure to welding gases can cause health adverse effects. Risk assessment is a useful tool for good assessment of exposed workers. The purpose of this study was to determine the risk levels for exposed welders to welding gases. Welders (n=239) were selected from Iranian Natural Gas Transmission Pipelines Industry from four regions in Iran including Assaluyeh, Omidieh, Loshan, and Borujen. Ozone (O3) and nitrogen dioxide (NO2) samples were collected according to the OSHA ID-214 method and the NIOSH analytical method 6014, respectively. Direct reading instruments were used for sampling of carbon monoxide (CO) and carbon dioxide (CO2). A semi-quantitative method was used for risk assessment. Exposure to O3, NO2, CO, and CO2 ranged 0-0.0371, 0.01-0.58, 0.375-4.33, and 89.5- 1395.44 ppm, respectively. Among welders, Back weld group had the maximum exposure to O3, CO, CO2, while, the maximum exposure to NO2 was seen for Filling group and then for Back weld group. Although average exposure values were significantly lower than Threshold Limit Values-Time Weighted Average (TLV-TWA) (p<0.05), the results of risk assessment showed that, control approaches should be applied for welders specially in Full pass, Filling, Filling cap, and Back weld groups due to their medium (M) and high (H) rank of risk.


Exposure; Welding gases; Risk assessment; Iran; Gas; Pipelines Industry

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Antonini JM, O'Callaghan JP, Miller DB. Development of an animal model to study the potential neurotoxic effects associated with welding fume inhalation. Neuro Toxicology 2006; 27(5): 745-751.

Yu KM, Topham N, Wang J, et al. Decreasing biotoxicity of fume particles produced in welding process. Journal of Hazardous Materials 2011; 185(2-3): 1587-1591.

Sriram K, Lin GX, Jefferson AM, et al. Dopaminergic neurotoxicity following pulmonary exposure to manganesecontaining welding fumes. Archiv Toxicolo 2010; 84(7): 521- 540.

National Institute for Occupational Safety and Health.Nomination of welding fumes for toxicity studies February 2002.

Palli D, Sera F, Giovannelli L, et al. Environmental ozone exposure and oxidative DNA damage in adult residents of Florence, Italy. Environmental Pollution 2009; 157(5): 1521-1525.

Yamauchi T, Shima M, Kuwaki T, et al. Acute effects of ozone exposure on lung function in mice sensitized to ovalbumin. Toxicology 2002; 172(1): 69-78.

Elsayed NM. Diet restriction modulates lung response and survivability of rats exposed to ozone. Toxicology 2001; 159(3): 171-182.

Ayyagari VN, Januszkiewicz A, Nath J. Pro-inflammatory responses of human bronchial epithelial cells to acute nitrogen dioxide exposure. Toxicology 2004; 197(2): 148-163.

Papi A, Amadesi S, Chitano P, et al. Bronchopulmonary inflammation and airway smooth muscle hyperresponsiveness induced by nitrogen dioxide in guinea pigs. Eur J Pharmacol 1999; 374(2): 241-247.

Raub JA. Health effects of exposure to ambient carbon monoxide. Chemosphere - Global Change Science 1999; 1(1-3): 331-351.

Raub JA, Mathieu NM, Hampson NB, Thom SR. Carbon monoxide poisoning -- a public health perspective. Toxicology 2000; 145(1): 1-14.

Scott JL, Kraemer DG, Keller RJ. Occupational hazards of carbon dioxide exposure. Journal of Chemical Health and Safety 2009; 16(2): 18-22.

Curran CP, Park RM, Ho SM, Haynes EN. Incorporating genetics and genomics in risk assessment for inhaled manganese: From data to policy. Neuro Toxicology 2009; 30(5): 754-760.

Zalk DM, Nelson DI. History and evolution of control banding: a review. J Occup Environ Hyg 2008; 5(5): 330-46.

Ministry of Manpower, Occupational Safety and Health Division. A semi-quantitative method to assess occupational exposure to harmful chemicals, Singapore, 2005.

Schoonover T, Conroy L, Lacey S, Plavka J. Personal exposure to metal fume, NO2, and O3 among production welders and nonwelders. Ind Health 2011; 49(1): 63-72.

Saito H, Ojima J, Takaya M, et al. Laboratory measurement of hazardous fumes and gases at a point corresponding to breathing zone of welder during a CO2 arc welding. Ind Health 2000; 38(1): 69-78.

Jenkins HS, Devalia JL, Mister RL, Bevan AM, Rusznak C, Davies RJ. The effect of exposure to ozone and nitrogen dioxide on the airway response of atopic asthmatics to inhaled allergen: dose- and time-dependent effects. Am J Respir Crit Care Med 1999; 160(1): 33-9.

Kreit JW, Gross KB, Moore TB, Lorenzen TJ, D’Arcy J, Eschenbacher WL. Ozone-induced changes in pulmonary function and bronchial responsiveness in asthmatics. J Appl Physiol 1989; 66(1): 217-22.

Aris RM CD, Hearne PQ, Kerr K, Finkbeiner WE, Balmes JR, Ozone-induced airway inflammation in human subjects as determined by airway lavage and biopsy. Am Rev Respir Dis 1993; 148(5): 1363-72.

Scannell C, Chen L, Aris RM, et al. Greater ozone-induced inflammatory responses in subjects with asthma. Am J Respir Crit Care Med 1996; 154(1): 24-9.

Latza U, Gerdes S, Baur X, Effects of nitrogen dioxide on human health: Systematic review of experimental and epidemiological studies conducted between 2002 and 2006. Int J Hyg Environ Health 2009; 212(3): 271-287.

Halpern P, Raskin Y, Sorkine P, Oqanezov A. Exposure to extremely high concentrations of carbon dioxide: A clinical description of a mass casualty incident. Ann Emerg Med 2004; 43(2): 196-199.


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